Crown Gall Tumor and Root Nodule Formation by the Bacterium Phyllobacterium myrsinacearum after the Introduction of an Agrobacterium Ti Plasmid or a Rhizobium Sym Plasmid. R. J. M. van Veen. Department of Plant Molecular Biology, MolBas Research Group, Leiden University, Wassenaarseweg 64, 2333 AL Leiden The Netherlands. H. den Dulk-Ras(1), T. Bisselling(2), R. A. Schilperoort(1), and P. J. J. Hooykaas(1). (1) Department of Plant Molecular Biology, MolBas Research Group, Leiden University, Wassenaarseweg 64, 2333 AL Leiden, The Netherlands, (2) Department of Molecular Biology, Agricultural University, De Dreyen 11, 6703 BC Wageningen, The Netherlands.. MPMI 1:231-234. Accepted 12 August 1988. Copyright 1988 The American Phytopathological Society.

Phyllobacterium rubiacearum and P. myrsinacearum are symbiotic bacteria that can be isolated from the leaf nodules of members of the plant families Rubiaceae and Myrsinaceae, respectively. They are classified as belonging to the bacterial family Rhizobiaceae. We found that P. myrsinacearum becomes able to induce crown gall tumors upon receipt of a Ti plasmid from Agrobacterium tumefaciens. Moreover, the introduction of the Sym plasmid pRL1JI from Rhizobium leguminosarum conferred on this bacterium the ability to nodulate the legume Vicia sativa. These results show that the host range of Ti and Sym plasmids includes the genus Phyllobacterium. They also indicate that chromosomal genes involved in tumorigenesis and nodule formation are functionally present in Phyllobacterium. Our data confirm the classification of Phyllobacterium in the Rhizobiaceae family.